Lesson 22 / 25

Advanced performance techniques

Explore advanced patterns and techniques for extreme performance optimization.

WebAssembly for performance-critical code

Compile C++, Rust to WebAssembly for 10-50x speedup on compute-heavy tasks (image processing, 3D). Compile once, run across browsers. Ideal for math, physics, data processing. Typical WASM module: 30-100KB gzipped.

Server-side rendering and static generation

SSR: render on server, send HTML+data. Faster FCP than client-side. SSG: pre-render at build time, serve static HTML. Best for content sites. ISR (Incremental Static Regeneration) updates static pages on-demand without full rebuild.

Choosing optimization techniques

Profile first, optimize second. Not all optimizations help all sites. SSR helps FCP, may hurt TTI. WASM helps computation, not layout. Choose based on measurements, not assumptions.

Quick check

Quick check: What does WebAssembly help optimize?

All JavaScript code
Layout rendering
Compute-heavy tasks for 10-50x speedup
DOM updates only

Answer

Compute-heavy tasks for 10-50x speedup — WebAssembly suits CPU-heavy work like image processing, not layout or DOM work.